My invention is a short motion swim fin that functions as a stretching device to stretch and increase the arch of the foot, and as a training device to strengthen the leg muscles that are used with the motions of the flutter kick.
My invention differs in design, function, and mechanics from all prior art seen relating to swim fins, wherein it is a training device for the competitive swimmer; and not designed or intended as a more efficient propulsion device.
My invention is a training swim fin that when used over time will improve a swimmer's performance for competitive swimming without the fins.
My invention is intended and designed specifically for use with the flutter kick, which is a short, fast motion kick, used for the front or back crawl whereby the body is parallel to the surface of the water with the legs moving up and down from the hips, in short, fast motions, knees slightly bending, and the feet kept loose. The extent of flexible arching of the feet is the critical element for converting the leg motion into propulsion by presenting an angle of attack from the loosely arching foot on every downward kick. The downward kick is the power portion of the flutter kick, whereas the upward motion is more for balance and recovery. The loosely arching foot functions, if you will, as a propeller blade. In fact many swimmers have a flutter kick that defines a spiral wake as a result of a well-defined arch. Although my swim fins produce an impressive increase in propulsion, they do so as a result of a short, fast, kicking motion, and accordingly are not designed or intended to conserve energy.
Whereas the relevant art studied discloses swim fins that are, for the most part, designed to function for underwater diving. And as such function for the purpose of propulsion efficiency in order to conserve energy, and they do so by using a common principle whereby the fin, in one form or another, is worn as a flexible extension of the foot so that the fin itself presents a greater surface, and angle of attack, against the water. This principle is well suited where conservation of energy, or air supply, is the primary consideration; but these fins also require a slower, longer kicking motion, or if you will, comparable to using a large gear for power to a smaller gear for speed. And accordingly, these fins are not practical for the short, fast kicking motions of the flutter kick, or more specifically, as a training device for competitive swimming without fins.
In addition to the originality for use of my invention, there is also originality in the design and mechanics. Specifically, it is a short fin that has a rigid U shape frame, that when worn on the forward portion of the foot acts as a lever to the foot with the fulcrum of that lever being on the underside of the foot. The effect of this lever action stretches the arch of the foot on every downward kick.
None of the prior art seen can be practically used, or is disclosed to be used, in a similar way as my invention, specifically, as a stretching and training fin for the competitive swimmer, and in particular for the short motions of the flutter kick used in competitive swimming.
None of the prior art seen employ the same mechanics, or make any similar claims of the mechanics, from a swim fin with a rigid frame to lever the arch of the foot.
Whereas all the prior art seen have as a common objective to be used in a dynamic fashion for moving a swimmer through the water more efficiently.
The following U.S. patents are considered most relevant to my disclosure:
______________________________________ U.S. Pat. No. Inventor Issue Date ______________________________________ 5,597,336 Evans Jan. 28, 1997 5,552,748 Cressi Jun. 4, 1996 3,789,448 Mitchell Feb. 5, 1974 2,556,894 Axiotes Jun. 12, 1951 ______________________________________
The following U.S. patents are included as being of interest:
______________________________________ 5,683,279 Raasch et. al. Nov. 4, 1997 3,302,223 Ciccotelli Feb. 7, 1967 1,674,801 Schwalge Jun, 26, 1928 3,922,740 Potter Dec. 2, 1975 2,672,629 Trell Mar. 23, 195 ______________________________________
A profile of each of these patents is as follows:
U.S. Pat. No. 5,597,336
Has an open instep, with planar heel, so as to accommodate a plurality of foot sizes and simplification of a single, two parts, molding process.
It is designed as a propulsion enhancement device with an elongated, flexible blade that has stiffening ribs under the foot, along the longitudinal axis of the fin, and also features unique protuberances to further reduce drag upon the blade surface.
U.S. Pat. No. 5,522,748
Is a three-part swim fm that has all the parts joined along the bottom of the shoe.
A full shoe attached to a forked, arcuate part that holds an elongated fin. And this arrangement is primarily intended to reduce the costs of production as compared to that of molded rubber fins.
And a flipper for enhancing propulsion, wherein the fin has an elongated, flexible, obtuse angle to the shoe, or bottom of the foot.
U.S. Pat. No. 3,789,448
A swimming aid for hand and foot propulsion that works on foot propulsion by using the legs in a pedaling, or climbing motion, whereby its design causes a stronger push against the water on the backward motion than it does on the forward motion.
U.S. Pat. No. 2,556,894
A swimming device for hand and foot propulsion that works on foot propulsion by using the legs in a pedaling, or climbing motion, whereby the device is kept in a perpendicular attitude to the leg on the backward motion to push against the water, and straightened, or feathered, on the forward motion for less resistance.
U.S. Pat. No. 5,683,279
Is a multi-part diving fin designed for propulsion enhancement with a pivotal footplate that engages the blade, or fin portion, in a manner that allows for adjusting the tension of the elongated blade according to the swimmer's ability.
This fin also has an alternate embodiment to accommodate diving boots.
U.S. Pat. No. 3,302,223
Is a swim fin comprising a full boot with a rigid, flat sole plate that hinges a U shape element, holding a flexible web, as the fin portion. The swimming motion of the leg causes the frame to move up and down independently from the motion or position of the boot, and in a manner that is a tensioned cantilever, so arranged as to present a greater angle of attack to the water on the downward motion than on the upward motion.
This swim fin is designed to enhance propulsion with minimal strain to the foot.
U.S. Pat. No. 1,674,801
Is a swimming appliance that is used with a pedaling or climbing motion whereby the pushing direction offers more resistance to the water than the pulling direction resulting in horizontal or vertical propulsion.
This swimming appliance also features a reinforced sole that is suitable for limited walking out of the water.
U.S. Pat. No. 3,922,740
This is a hand paddle and not applicable for wearing on the foot.
U.S. Pat. No. 2,672,629
Is a swimmer's propulsion aid that is used with a pedaling or climbing motion whereby the pushing direction offers more resistance to the water than the pulling direction resulting in a horizontal or vertical propulsion.